The SSH connection may hang indefinitely when trying to connect. Attempts to stop the connection with Control-C may or may not return you to a shell prompt. If you run ssh-vvvvphablet@10.15.19.82, you only get the following output before the program stops:

This seems to be a common error on arm64 devices with kernel 3.10 when rsyslogd is enabled. If you have this error, please add your voice to ubports/ubuntu-touch#560 and then try the following workaround: